Power awareness measurement in time division synchronous code division multiple access

ABSTRACT

A user equipment may save power by reducing certain battery draining activities when the battery power remaining in the UE fails to meet a threshold value. The UE may skip inter-radio access technology measurements to conserve battery life when the battery power in the UE fails to meet the threshold. The UE may also extend inter-radio access technology measurement periodicity when the battery power in the UE fails to meet the threshold.

BACKGROUND

1. Field

Aspects of the present disclosure relate generally to wirelesscommunication systems, and more particularly, to power awarenessmeasurement in time division synchronous code division multiple access.

2. Background

Wireless communication networks are widely deployed to provide variouscommunication services such as telephony, video, data, messaging,broadcasts, and so on. Such networks, which are usually multiple accessnetworks, support communications for multiple users by sharing theavailable network resources. One example of such a network is theUniversal Terrestrial Radio Access Network (UTRAN). The UTRAN is theradio access network (RAN) defined as a part of the Universal MobileTelecommunications System (UMTS), a third generation (3G) mobile phonetechnology supported by the 3rd Generation Partnership Project (3GPP).The UMTS, which is the successor to Global System for MobileCommunications (GSM) technologies, currently supports various airinterface standards, such as Wideband-Code Division Multiple Access(W-CDMA), Time Division-Code Division Multiple Access (TD-CDMA), andTime Division-Synchronous Code Division Multiple Access (TD-SCDMA). Forexample, China is pursuing TD-SCDMA as the underlying air interface inthe UTRAN architecture with its existing GSM infrastructure as the corenetwork. The UMTS also supports enhanced 3G data communicationsprotocols, such as High Speed Packet Access (HSPA), which provideshigher data transfer speeds and capacity to associated UMTS networks.HSPA is a collection of two mobile telephony protocols, High SpeedDownlink Packet Access (HSDPA) and High Speed Uplink Packet Access(HSUPA) that extends and improves the performance of existing widebandprotocols.

As the demand for mobile broadband access continues to increase,research and development continue to advance the UMTS technologies notonly to meet the growing demand for mobile broadband access, but toadvance and enhance the user experience with mobile communications.

SUMMARY

According to one aspect of the present disclosure, a method for wirelesscommunication includes determining when a remaining battery power of aUE is lower than a first threshold value. The method may also includeincreasing a periodicity of inter-radio access technology (inter-RAT)measurements when the battery power is lower than the first thresholdvalue.

According to another aspect of the present disclosure, an apparatus forwireless communication includes means for determining when a remainingbattery power of a UE is lower than a first threshold value. Theapparatus may also include means for increasing a periodicity ofinter-radio access technology (inter-RAT) measurements when the batterypower is lower than the first threshold value.

According to one aspect of the present disclosure, a computer programproduct for wireless communication in a wireless network includes acomputer readable medium having non-transitory program code recordedthereon. The program code includes program code to determine when aremaining battery power of a UE is lower than a first threshold value.The program code also includes program code to increase a periodicity ofinter-radio access technology (inter-RAT) measurements when the batterypower is lower than the first threshold value.

According to one aspect of the present disclosure, an apparatus forwireless communication includes a memory and a processor(s) coupled tothe memory. The processor(s) is configured to determine when a remainingbattery power of a UE is lower than a first threshold value. Theprocessor(s) is further configured to increase a periodicity ofinter-radio access technology (inter-RAT) measurements when the batterypower is lower than the first threshold value.

This has outlined, rather broadly, the features and technical advantagesof the present disclosure in order that the detailed description thatfollows may be better understood. Additional features and advantages ofthe disclosure will be described below. It should be appreciated bythose skilled in the art that this disclosure may be readily utilized asa basis for modifying or designing other structures for carrying out thesame purposes of the present disclosure. It should also be realized bythose skilled in the art that such equivalent constructions do notdepart from the teachings of the disclosure as set forth in the appendedclaims. The novel features, which are believed to be characteristic ofthe disclosure, both as to its organization and method of operation,together with further objects and advantages, will be better understoodfrom the following description when considered in connection with theaccompanying figures. It is to be expressly understood, however, thateach of the figures is provided for the purpose of illustration anddescription only and is not intended as a definition of the limits ofthe present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram conceptually illustrating an example of atelecommunications system.

FIG. 2 is a block diagram conceptually illustrating an example of aframe structure in a telecommunications system.

FIG. 3 is a block diagram conceptually illustrating an example of a nodeB in communication with a UE 350 in a telecommunications system.

FIG. 4 illustrates a geographical area with coverage from three radioaccess technologies according to one aspect of the present disclosure.

FIG. 5 is a block diagram illustrating a power awareness measurementmethod for time division synchronous code division multiple accessaccording to one aspect of the present disclosure.

FIG. 6 is a diagram illustrating an example of a hardware implementationfor an apparatus employing a processing system.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with theappended drawings, is intended as a description of variousconfigurations and is not intended to represent the only configurationsin which the concepts described herein may be practiced. The detaileddescription includes specific details for the purpose of providing athorough understanding of the various concepts. However, it will beapparent to those skilled in the art that these concepts may bepracticed without these specific details. In some instances, well-knownstructures and components are shown in block diagram form in order toavoid obscuring such concepts.

Turning now to FIG. 1, a block diagram is shown illustrating an exampleof a telecommunications system 90. The various concepts presentedthroughout this disclosure may be implemented across a broad variety oftelecommunication systems, network architectures, and communicationstandards. By way of example and without limitation, the aspects of thepresent disclosure illustrated in FIG. 1 are presented with reference toa UMTS system employing a TD-SCDMA standard. In this example, the UMTSsystem includes a (radio access network) RAN 102 (e.g., UTRAN) thatprovides various wireless services including telephony, video, data,messaging, broadcasts, and/or other services. The RAN 102 may be dividedinto a number of Radio Network Subsystems (RNSs) such as an RNS 107,each controlled by a Radio Network Controller (RNC) such as an RNC 106.For clarity, only the RNC 106 and the RNS 107 are shown; however, theRAN 102 may include any number of RNCs and RNSs in addition to the RNC106 and RNS 107. The RNC 106 is an apparatus responsible for, amongother things, assigning, reconfiguring and releasing radio resourceswithin the RNS 107. The RNC 106 may be interconnected to other RNCs (notshown) in the RAN 102 through various types of interfaces such as adirect physical connection, a virtual network, or the like, using anysuitable transport network.

The geographic region covered by the RNS 107 may be divided into anumber of cells, with a radio transceiver apparatus serving each cell. Aradio transceiver apparatus is commonly referred to as a node B in UMTSapplications, but may also be referred to by those skilled in the art asa base station (BS), a base transceiver station (BTS), a radio basestation, a radio transceiver, a transceiver function, a basic serviceset (BSS), an extended service set (ESS), an access point (AP), or someother suitable terminology. For clarity, two node Bs 108 are shown;however, the RNS 107 may include any number of wireless node Bs. Thenode Bs 108 provide wireless access points to a core network 104 for anynumber of mobile apparatuses. Examples of a mobile apparatus include acellular phone, a smart phone, a session initiation protocol (SIP)phone, a laptop, a notebook, a netbook, a smartbook, a personal digitalassistant (PDA), a satellite radio, a global positioning system (GPS)device, a multimedia device, a video device, a digital audio player(e.g., MP3 player), a camera, a game console, or any other similarfunctioning device. The mobile apparatus is commonly referred to as userequipment (UE) in UMTS applications, but may also be referred to bythose skilled in the art as a mobile station (MS), a subscriber station,a mobile unit, a subscriber unit, a wireless unit, a remote unit, amobile device, a wireless device, a wireless communications device, aremote device, a mobile subscriber station, an access terminal (AT), amobile terminal, a wireless terminal, a remote terminal, a handset, aterminal, a user agent, a mobile client, a client, or some othersuitable terminology. For illustrative purposes, three UEs 110 are shownin communication with the node Bs 108. The downlink (DL), also calledthe forward link, refers to the communication link from a node B to aUE, and the uplink (UL), also called the reverse link, refers to thecommunication link from a UE to a node B.

The core network 104, as shown, includes a GSM core network. However, asthose skilled in the art will recognize, the various concepts presentedthroughout this disclosure may be implemented in a RAN, or othersuitable access network, to provide UEs with access to types of corenetworks other than GSM networks.

In this example, the core network 104 supports circuit-switched serviceswith a mobile switching center (MSC) 112 and a gateway MSC (GMSC) 114.One or more RNCs, such as the RNC 106, may be connected to the MSC 112.The MSC 112 is an apparatus that controls call setup, call routing, andUE mobility functions. The MSC 112 also includes a visitor locationregister (VLR) (not shown) that contains subscriber-related informationfor the duration that a UE is in the coverage area of the MSC 112. TheGMSC 114 provides a gateway through the MSC 112 for the UE to access acircuit-switched network 116. The GMSC 114 includes a home locationregister (HLR) (not shown) containing subscriber data, such as the datareflecting the details of the services to which a particular user hassubscribed. The HLR is also associated with an authentication center(AuC) that contains subscriber-specific authentication data. When a callis received for a particular UE, the GMSC 114 queries the HLR todetermine the UE's location and forwards the call to the particular MSCserving that location.

The core network 104 also supports packet-data services with a servingGPRS support node (SGSN) 118 and a gateway GPRS support node (GGSN) 120.GPRS, which stands for General Packet Radio Service, is designed toprovide packet-data services at speeds higher than those available withstandard GSM circuit-switched data services. The GGSN 120 provides aconnection for the RAN 102 to a packet-based network 122. Thepacket-based network 122 may be the Internet, a private data network, orsome other suitable packet-based network. The primary function of theGGSN 120 is to provide the UEs 110 with packet-based networkconnectivity. Data packets are transferred between the GGSN 120 and theUEs 110 through the SGSN 118, which performs primarily the samefunctions in the packet-based domain as the MSC 112 performs in thecircuit-switched domain.

The UMTS air interface is a spread spectrum Direct-Sequence CodeDivision Multiple Access (DS-CDMA) system. The spread spectrum DS-CDMAspreads user data over a much wider bandwidth through multiplication bya sequence of pseudorandom bits called chips. The TD-SCDMA standard isbased on such direct sequence spread spectrum technology andadditionally calls for a time division duplexing (TDD), rather than afrequency division duplexing (FDD) as used in many FDD mode UMTS/W-CDMAsystems. TDD uses the same carrier frequency for both the uplink (UL)and downlink (DL) between a node B 108 and a UE 110, but divides uplinkand downlink transmissions into different time slots in the carrier.

FIG. 2 shows a frame structure 200 for a TD-SCDMA carrier. The TD-SCDMAcarrier, as illustrated, has a frame 202 that is 10 ms in length. Thechip rate in TD-SCDMA is 1.28 Mcps. The frame 202 has two 5 ms subframes204, and each of the subframes 204 includes seven time slots, TS0through TS6. The first time slot, TS0, is usually allocated for downlinkcommunication, while the second time slot, TS1, is usually allocated foruplink communication. The remaining time slots, TS2 through TS6, may beused for either uplink or downlink, which allows for greater flexibilityduring times of higher data transmission times in either the uplink ordownlink directions. A downlink pilot time slot (DwPTS) 206, a guardperiod (GP) 208, and an uplink pilot time slot (UpPTS) 210 (also knownas the uplink pilot channel (UpPCH)) are located between TS0 and TS1.Each time slot, TS0-TS6, may allow data transmission multiplexed on amaximum of 16 code channels. Data transmission on a code channelincludes two data portions 212 (each with a length of 352 chips)separated by a midamble 214 (with a length of 144 chips) and followed bya guard period (GP) 216 (with a length of 16 chips). The midamble 214may be used for features, such as channel estimation, while the guardperiod 216 may be used to avoid inter-burst interference. Alsotransmitted in the data portion is some Layer 1 control information,including Synchronization Shift (SS) bits 218. Synchronization Shiftbits 218 only appear in the second part of the data portion. TheSynchronization Shift bits 218 immediately following the midamble canindicate three cases: decrease shift, increase shift, or do nothing inthe upload transmit timing. The positions of the SS bits 218 are notgenerally used during uplink communications.

FIG. 3 is a block diagram of a node B 310 in communication with a UE 350in a RAN 300, where the RAN 300 may be the RAN 102 in FIG. 1, the node B310 may be the node B 108 in FIG. 1, and the UE 350 may be the UE 110 inFIG. 1. In the downlink communication, a transmit processor 320 mayreceive data from a data source 312 and control signals from acontroller/processor 340. The transmit processor 320 provides varioussignal processing functions for the data and control signals, as well asreference signals (e.g., pilot signals). For example, the transmitprocessor 320 may provide cyclic redundancy check (CRC) codes for errordetection, coding and interleaving to facilitate forward errorcorrection (FEC), mapping to signal constellations based on variousmodulation schemes (e.g., binary phase-shift keying (BPSK), quadraturephase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadratureamplitude modulation (M-QAM), and the like), spreading with orthogonalvariable spreading factors (OVSF), and multiplying with scrambling codesto produce a series of symbols. Channel estimates from a channelprocessor 344 may be used by a controller/processor 340 to determine thecoding, modulation, spreading, and/or scrambling schemes for thetransmit processor 320. These channel estimates may be derived from areference signal transmitted by the UE 350 or from feedback contained inthe midamble 214 (FIG. 2) from the UE 350. The symbols generated by thetransmit processor 320 are provided to a transmit frame processor 330 tocreate a frame structure. The transmit frame processor 330 creates thisframe structure by multiplexing the symbols with a midamble 214 (FIG. 2)from the controller/processor 340, resulting in a series of frames. Theframes are then provided to a transmitter 332, which provides varioussignal conditioning functions including amplifying, filtering, andmodulating the frames onto a carrier for downlink transmission over thewireless medium through smart antennas 334. The smart antennas 334 maybe implemented with beam steering bidirectional adaptive antenna arraysor other similar beam technologies.

At the UE 350, a receiver 354 receives the downlink transmission throughan antenna 352 and processes the transmission to recover the informationmodulated onto the carrier. The information recovered by the receiver354 is provided to a receive frame processor 360, which parses eachframe, and provides the midamble 214 (FIG. 2) to a channel processor 394and the data, control, and reference signals to a receive processor 370.The receive processor 370 then performs the inverse of the processingperformed by the transmit processor 320 in the node B 310. Morespecifically, the receive processor 370 descrambles and despreads thesymbols, and then determines the most likely signal constellation pointstransmitted by the node B 310 based on the modulation scheme. These softdecisions may be based on channel estimates computed by the channelprocessor 394. The soft decisions are then decoded and deinterleaved torecover the data, control, and reference signals. The CRC codes are thenchecked to determine whether the frames were successfully decoded. Thedata carried by the successfully decoded frames will then be provided toa data sink 372, which represents applications running in the UE 350and/or various user interfaces (e.g., display). Control signals carriedby successfully decoded frames will be provided to acontroller/processor 390. When frames are unsuccessfully decoded by thereceiver processor 370, the controller/processor 390 may also use anacknowledgement (ACK) and/or negative acknowledgement (NACK) protocol tosupport retransmission requests for those frames.

In the uplink, data from a data source 378 and control signals from thecontroller/processor 390 are provided to a transmit processor 380. Thedata source 378 may represent applications running in the UE 350 andvarious user interfaces (e.g., keyboard). Similar to the functionalitydescribed in connection with the downlink transmission by the node B310, the transmit processor 380 provides various signal processingfunctions including CRC codes, coding and interleaving to facilitateFEC, mapping to signal constellations, spreading with OVSFs, andscrambling to produce a series of symbols. Channel estimates, derived bythe channel processor 394 from a reference signal transmitted by thenode B 310 or from feedback contained in the midamble transmitted by thenode B 310, may be used to select the appropriate coding, modulation,spreading, and/or scrambling schemes. The symbols produced by thetransmit processor 380 will be provided to a transmit frame processor382 to create a frame structure. The transmit frame processor 382creates this frame structure by multiplexing the symbols with a midamble214 (FIG. 2) from the controller/processor 390, resulting in a series offrames. The frames are then provided to a transmitter 356, whichprovides various signal conditioning functions including amplification,filtering, and modulating the frames onto a carrier for uplinktransmission over the wireless medium through the antenna 352.

The uplink transmission is processed at the node B 310 in a mannersimilar to that described in connection with the receiver function atthe UE 350. A receiver 335 receives the uplink transmission through theantenna 334 and processes the transmission to recover the informationmodulated onto the carrier. The information recovered by the receiver335 is provided to a receive frame processor 336, which parses eachframe, and provides the midamble 214 (FIG. 2) to the channel processor344 and the data, control, and reference signals to a receive processor338. The receive processor 338 performs the inverse of the processingperformed by the transmit processor 380 in the UE 350. The data andcontrol signals carried by the successfully decoded frames may then beprovided to a data sink 339 and the controller/processor, respectively.If some of the frames were unsuccessfully decoded by the receiveprocessor, the controller/processor 340 may also use an acknowledgement(ACK) and/or negative acknowledgement (NACK) protocol to supportretransmission requests for those frames.

The controller/processors 340 and 390 may be used to direct theoperation at the node B 310 and the UE 350, respectively. For example,the controller/processors 340 and 390 may provide various functionsincluding timing, peripheral interfaces, voltage regulation, powermanagement, and other control functions. The processor 340/390 and/orother processors and modules at the node B 310/UE 350 may perform ordirect the execution of the functional blocks illustrated in FIG. 5. Thecomputer readable media of memories 342 and 392 may store data andsoftware for the node B 310 and the UE 350, respectively. For example,the memory 392 of the UE 350 may store power awareness measurementmodule 391 which, when executed by the controller/processor 390,configures the UE 350 for building high speed shared information controlchannels (HS-SICHS) in multi-carrier time division high speed downlinkpacket access (HSDPA) systems as described. A scheduler/processor 346 atthe node B 310 may be used to allocate resources to the UEs and scheduledownlink and/or uplink transmissions for the UEs.

Deployment of a TD-SCDMA network may not provide complete geographiccoverage in certain areas during the migration, e.g., from 2G to 3G orfrom 3G to 4G, Radio Access Technologies (RATs). In areas where TD-SCDMAnetworks are deployed, other networks (such as WCDMA and Global Systemfor Mobile Communications (GSM)) may also have a geographical presence.FIG. 4 illustrates a geographical area with coverage from three radioaccess technologies according to one aspect. In this deployment of anetwork, e.g., TD-SCDMA systems, the UE may be in the vicinity of theTD-SCDMA network but continue to perform inter-radio access technology(inter-RAT) measurement of other radio access technologies, e.g., GSM,WCDMA or LTE network. This measurement may be implemented for a cell orbase station reselection procedure from the TD-SCDMA cell to theGSM/WCDMA/LTE cell. Inter-RAT measurement may be implemented, forexample, due to limited coverage of TD-SCDMA or when the UE 350 desiresa better RAT, e.g., LTE, for higher data rate during transmission.

A first network coverage area 410 partially overlaps with a secondnetwork coverage area 420 and a third network coverage area 430. In oneaspect, the first network coverage area 410 is a TD-SCDMA network, thesecond network coverage area 420 is a WCDMA network, and the thirdnetwork coverage area 430 is a GSM network. Thus, a multimode UE 402 maybenefit from being able to communicate with the TD-SCDMA network 410,the WCDMA network 420, and the GSM network 430. According to one aspect,the multimode UE 402 may communicate with a TD-SCDMA NB 412, a WCDMA BTS422, and/or a GSM BTS 432. For example, the multimode UE 402 may haveseveral Subscriber Identity Modules (SIMs): one SIM for WCDMA, one SIMfor TD-SCDMA, and one SIM for GSM.

Generally, the different networks may have certain advantages anddisadvantages. For example, the GSM network 430 provides maturedcircuit-switched services, which is advantageous for voice calls. Thatis, the GSM network 430 may offer more network coverage to allowun-disrupted voice call services in handovers. As another example, theWCDMA network 420 and the TD-SCDMA network 410 provide high performancepacket-switched services, which is advantageous for data calls. That is,the WCDMA network 420 and the TD-SCDMA network 410 may offer higher datarates for data call services.

As the UE 402 moves from an old geographical area 442 to a newgeographical area 444, the UE 402 may be in communication with a firsttype of network and handover to a different type of network. Forexample, the UE 402 may move from the TD-SCDMA network 410 in an oldgeographical area 442 to a new geographical area 444, which offers theGSM network 430 and the WCDMA network 420. When multiple networks areavailable in the new geographical area 444, the UE 402 selects one ofthe networks as the target RAT for inter-RAT handover of the UE 402.

Power Awareness Measurement in Time Division Synchronous Code DivisionMultiple Access

During wireless communication, user equipments (UEs) 350 may besporadically active and may remain idle for significant periods of timewhen no call is in progress. However, to ensure that any messagedirected to the UE 350 is received, the UE 350 periodically monitors thecommunication channel for messages (e.g., paging messages or signalstransmitted by a base station 310), even while the UE is idle. Themessages may include those for alerting the UE 350 to the presence of anincoming call, those for updating system parameters in the UE 350,and/or instructions for measuring signals of radio access technologies(RAT) of neighboring base stations (i.e., inter-RAT measurements).

To reduce power consumption in a UE 350 operating in idle mode, the UE350 may periodically enter an active state during which it may receivemessages on a paging channel from the base stations 310 with which ithas previously established communication. The paging channel may bedivided into numbered frames (e.g., frames 0 through 1023) and the UE350 may be assigned one or more frames by the base stations 310.Thereafter, the UE 350 may awaken from an inactive state prior to itsassigned frame, monitor the paging channels for messages, and revert tothe inactive state if additional communication is not desired. Thus, theUE 350 monitors paging messages from the base station 310 informing theUE 350 of possible incoming transmissions. In the time period betweensuccessive active states, the UE 350 is in the inactive state and thebase station 310 does not send any messages to the UE 350. The timebetween two consecutive paging message is called a discontinuous receive(DRX) period or cycle. In the inactive state, as much circuitry aspossible may be powered down to conserve power.

During the wireless communication, UEs 350 may desire to measure thesignal of radio access technologies (RATs) of neighboring base stations310 in a discontinuous receive (DRX) cycle after monitoring the pagingchannel. Such inter-RAT measurements may be made at specified timeperiods or during certain situations or conditions that trigger theinter-RAT measurements. The UE 350 may perform inter-RAT measurements ofother radio access technologies (e.g., TD-SCDMA or GSM) supported by aneighboring base station when a UE 350 receives a neighbor list messageindicating the nearby RATs.

During idle mode, a UE 350 may continue to consume power to performinter-RAT measurements. Many UEs 350 are portable and powered by aninternal battery. The inter-RAT measurement power consumption by the UE350 in the idle mode decreases the available battery resources. As aresult, it is may be desirable to reduce power consumption in the UE 350in the idle state to increase battery life.

In one aspect of the present disclosure, when the battery powerremaining in the UE 350 fails to meet a first threshold value, the UE350 skips inter-RAT measurements (e.g., inter-RAT measurements of GSMfrom TD-SCDMA). For example, the UE 350 skips inter-RAT measurementswhen the battery power is below the first threshold value, e.g., lessthan twenty percent of the battery life. Skipping or eliminatinginter-RAT measurements in such situations may conserve UE 350 batterypower and improve performance.

In one aspect of the present disclosure, when battery power remaining inthe UE 350 fails to meet a second threshold value, the UE 350 extends oradjusts the inter-RAT measurement periods. In this implementation, theUE 350 may extend the inter-RAT measurement period even when the UE 350receives inter-RAT measurement instructions from the base station 310supporting a shorter inter-RAT measurement periods. The first thresholdvalue may be the same or different from the second threshold value. Forexample, the UE 350 may extend the inter-RAT measurement period when thebattery power is less than twenty percent of the battery life or whenthe battery power is less than ten percent of the battery life. Thus,when battery power remaining in the UE 350 fails to meet the firstand/or the second threshold value, the UE 350 may skip inter-RATmeasurement and/or extends the inter-RAT measurement period.

In one aspect of the present disclosure, when battery power remaining inthe UE 350 fails to meet a third threshold value and when the signalstrength of a serving base station 310 is sufficient to support UE 350communication, the UE 350 skips inter-RAT measurements. For example, theUE 350 may perform inter-RAT measurements when the signal strength ofthe serving base station 310 is below a signal strength threshold valueand when the battery power is below the third threshold value. The thirdthreshold value may be the same or different from the second thresholdvalue or the first threshold value. As a result of the power awarenessmeasurement implementations, the battery power of the UE 350 may beconserved and the UE 350 performance improved.

As shown in FIG. 5 a UE may determine when a remaining battery power ofa UE is lower than a first threshold value, as shown in block 502. A UE350 may increase a periodicity of inter-radio access technology(inter-RAT) measurements when the battery power is lower than the firstthreshold value, as shown in block 504.

FIG. 6 is a diagram illustrating an example of a hardware implementationfor an apparatus 600 employing a power awareness measurement system 614.The power awareness measurement system 614 may be implemented with a busarchitecture, represented generally by a bus 624. The bus 624 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the power awareness measurement system 614 andthe overall design constraints. The bus 624 links together variouscircuits including one or more processors and/or hardware modules,represented by a processor 626, a power determining module 602 and ameasurement periodicity adjustment module 604, and a computer-readablemedium 628. The bus 624 may also link various other circuits such astiming sources, peripherals, voltage regulators, and power managementcircuits, which are well known in the art, and therefore, will not bedescribed any further.

The apparatus includes the power awareness measurement system 614coupled to a transceiver 622. The transceiver 622 is coupled to one ormore antennas 620. The transceiver 622 provides a means forcommunicating with various other apparatus over a transmission medium.The power awareness measurement system 614 includes the processor 626coupled to the computer-readable medium 628. The processor 626 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium 628. The software, when executedby the processor 626, causes the power awareness measurement system 614to perform the various functions described supra for any particularapparatus. The computer-readable medium 628 may also be used for storingdata that is manipulated by the processor 626 when executing software.The power awareness measurement system 614 further includes the powerdetermining module 602 for determining when a remaining battery power ofa UE is lower than a first threshold value, and the measurementperiodicity adjustment module 604 for increasing a periodicity ofinter-radio access technology (inter-RAT) measurements. The powerdetermining module 602 and the measurement periodicity adjustment module604 may be software modules running in the processor 626,resident/stored in the computer-readable medium 628, one or morehardware modules coupled to the processor 626, or some combinationthereof. The power awareness measurement system 614 may be a componentof the UE 350 and may include the memory 392 and/or the processor 390.

In one configuration, the apparatus 600 for wireless communicationincludes means for determining. The means may be the power determiningmodule 602, the power awareness measurement module 391, the memory 392,the processor 390 and/or the power awareness measurement system 614 ofthe apparatus 600 configured to perform the functions recited by themeasuring and recording means. As described above, the power awarenessmeasurement system 614 may include the memory 392 and/or the processor390. In another aspect, the aforementioned means may be any module orany apparatus configured to perform the functions recited by theaforementioned means.

In one configuration, the apparatus 600 for wireless communicationincludes means for increasing. The means may be the measurementperiodicity adjustment module 604, the power awareness measurementmodule 391, the memory 392, the processor 390 and/or the power awarenessmeasurement system 614 of the apparatus 600 configured to perform thefunctions recited by the means. As described above, the power awarenessmeasurement system 614 may include the memory 392 and/or the processor390. In another aspect, the aforementioned means may be any module orany apparatus configured to perform the functions recited by theaforementioned means.

Several aspects of a telecommunications system has been presented withreference to TD-SCDMA systems. As those skilled in the art will readilyappreciate, various aspects described throughout this disclosure may beextended to other telecommunication systems, network architectures andcommunication standards. By way of example, various aspects may beextended to other UMTS systems such as W-CDMA, High Speed DownlinkPacket Access (HSDPA), High Speed Uplink Packet Access (HSUPA), HighSpeed Packet Access Plus (HSPA+) and TD-CDMA. Various aspects may alsobe extended to systems employing Long Term Evolution (LTE) (in FDD, TDD,or both modes), LTE-Advanced (LTE-A) (in FDD, TDD, or both modes),CDMA2000, Evolution-Data Optimized (EV-DO), Ultra Mobile Broadband(UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20,Ultra-Wideband (UWB), Bluetooth, and/or other suitable systems. Theactual telecommunication standard, network architecture, and/orcommunication standard employed will depend on the specific applicationand the overall design constraints imposed on the system.

Several processors have been described in connection with variousapparatuses and methods. These processors may be implemented usingelectronic hardware, computer software, or any combination thereof.Whether such processors are implemented as hardware or software willdepend upon the particular application and overall design constraintsimposed on the system. By way of example, a processor, any portion of aprocessor, or any combination of processors presented in this disclosuremay be implemented with a microprocessor, microcontroller, digitalsignal processor (DSP), a field-programmable gate array (FPGA), aprogrammable logic device (PLD), a state machine, gated logic, discretehardware circuits, and other suitable processing components configuredto perform the various functions described throughout this disclosure.The functionality of a processor, any portion of a processor, or anycombination of processors presented in this disclosure may beimplemented with software being executed by a microprocessor,microcontroller, DSP, or other suitable platform.

Software shall be construed broadly to mean instructions, instructionsets, code, code segments, program code, programs, subprograms, softwaremodules, applications, software applications, software packages,routines, subroutines, objects, executables, threads of execution,procedures, functions, etc., whether referred to as software, firmware,middleware, microcode, hardware description language, or otherwise. Thesoftware may reside on a computer-readable medium. A computer-readablemedium may include, by way of example, memory such as a magnetic storagedevice (e.g., hard disk, floppy disk, magnetic strip), an optical disk(e.g., compact disc (CD), digital versatile disc (DVD)), a smart card, aflash memory device (e.g., card, stick, key drive), random access memory(RAM), read only memory (ROM), programmable ROM (PROM), erasable PROM(EPROM), electrically erasable PROM (EEPROM), a register, or a removabledisk. Although memory is shown separate from the processors in thevarious aspects presented throughout this disclosure, the memory may beinternal to the processors (e.g., cache or register).

Computer-readable media may be embodied in a computer-program product.By way of example, a computer-program product may include acomputer-readable medium in packaging materials. Those skilled in theart will recognize how best to implement the described functionalitypresented throughout this disclosure depending on the particularapplication and the overall design constraints imposed on the overallsystem.

It is to be understood that the specific order or hierarchy of steps inthe methods disclosed is an illustration of exemplary processes. Basedupon design preferences, it is understood that the specific order orhierarchy of steps in the methods may be rearranged. The accompanyingmethod claims present elements of the various steps in a sample order,and are not meant to be limited to the specific order or hierarchypresented unless specifically recited therein.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language of the claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. A phrase referring to“at least one of” a list of items refers to any combination of thoseitems, including single members. As an example, “at least one of: a, b,or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, band c. All structural and functional equivalents to the elements of thevarious aspects described throughout this disclosure that are known orlater come to be known to those of ordinary skill in the art areexpressly incorporated herein by reference and are intended to beencompassed by the claims. Moreover, nothing disclosed herein isintended to be dedicated to the public regardless of whether suchdisclosure is explicitly recited in the claims. No claim element is tobe construed under the provisions of 35 U.S.C. §112, sixth paragraph,unless the element is expressly recited using the phrase “means for” or,in the case of a method claim, the element is recited using the phrase“step for.”

What is claimed is:
 1. A method of wireless communication, comprising:determining when a remaining battery power of a user equipment (UE) islower than a first threshold value and a second threshold value, thefirst threshold value differing from the second threshold value;receiving inter-radio access technology (IRAT) measurement instructionsfrom a base station for measuring signals of neighboring base stations;comparing a serving cell signal strength with a third threshold valuewhen the remaining battery power fails to meet the second thresholdvalue; eliminating IRAT measurements when the remaining battery power islower than the first threshold value; and extending a periodicity of theIRAT measurements when the remaining battery power is lower than thesecond threshold value and when the serving cell signal strength islarger than the third threshold value even when the IRAT measurementinstructions support a shorter IRAT measurement period.
 2. The method ofclaim 1, in which the determining and the extending occur when the UE isin idle mode.
 3. The method of claim 1, in which the IRAT measurementsare of a Global System for Mobile Communications (GSM) network andperformed by a user equipment connected to a Time Division-SynchronousCode Division Multiple Access (TD-SCDMA) network.
 4. An apparatus forwireless communication, comprising: means for determining when aremaining battery power of a user equipment (UE) is lower than a firstthreshold value and a second threshold value, the first threshold valuediffering from the second threshold value; means for receivinginter-radio access technology (IRAT) measurement instructions from abase station for measuring signals of neighboring base stations; meansfor comparing a serving cell signal strength with a third thresholdvalue when the remaining battery power fails to meet the secondthreshold value; means for eliminating IRAT measurements when theremaining battery power is lower than the first threshold value; andmeans for extending a periodicity of the IRAT measurements when theremaining battery power is lower than the second threshold value andwhen the serving cell signal strength is larger than the third thresholdvalue even when the IRAT measurement instructions support a shorter IRATmeasurement period.
 5. The apparatus of claim 4, in which thedetermining means further comprises means for determining when the UE isin idle mode and the extending means further comprises means forextending when the UE is in idle mode.
 6. The apparatus of claim 4, inwhich the IRAT measurements are of a Global System for MobileCommunications (GSM) network and performed by a user equipment connectedto a Time Division-Synchronous Code Division Multiple Access (TD-SCDMA)network.
 7. A computer-readable medium having non-transitory programcode recorded thereon, the program code comprising: program code todetermine when a remaining battery power of a user equipment (UE) islower than a first threshold value and a second threshold value, thefirst threshold value differing from the second threshold value; programcode to receive inter-radio access technology (IRAT) measurementinstructions from a base station for measuring signals of neighboringbase stations; program code to compare a serving cell signal strengthwith a third threshold value when the remaining battery power fails tomeet the second threshold value; program code to eliminate IRATmeasurements when the remaining battery power is lower than the firstthreshold value; and program code to extend a periodicity of the IRATmeasurements when the remaining battery power is lower than the secondthreshold value and when the serving cell signal strength is larger thanthe third threshold value even when the IRAT measurement instructionssupport a shorter IRAT measurement period.
 8. The computer-readablemedium of claim 7, in which the program code further comprises programcode to determine when the UE is in idle mode and program code to extendthe periodicity when the UE is in idle mode.
 9. The computer-readablemedium of claim 7, further comprising program code to measure IRATsignals of a Global System for Mobile Communications (GSM) network by auser equipment connected to a Time Division-Synchronous Code DivisionMultiple Access (TD-SCDMA) network.
 10. An apparatus for wirelesscommunication, comprising: a memory; and at least one processor coupledto the memory and configured: to determine when a remaining batterypower of a user equipment (UE) is lower than a first threshold value anda second threshold value, the first threshold value differing from thesecond threshold value; to receive inter-radio access technology (IRAT)measurement instructions from a base station for measuring signals ofneighboring base stations; to compare a serving cell signal strengthwith a third threshold value when the remaining battery power fails tomeet the second threshold value; to eliminate IRAT measurements when theremaining battery power is lower than the first threshold value; and toextend a periodicity of the IRAT measurements when the remaining batterypower is lower than the second threshold value and when the serving cellsignal strength is larger than the third threshold value even when theIRAT measurement instructions support a shorter IRAT measurement period.11. The apparatus of claim 10, in which the at least one processor isfurther configured to determine when the UE is in idle mode and toextend the periodicity when the UE is in idle mode.
 12. The apparatus ofclaim 10, in which the at least one processor is further configured tomeasure IRAT signals of a Global System for Mobile Communications (GSM)network by a user equipment connected to a Time Division-SynchronousCode Division Multiple Access (TD-SCDMA) network.